Annunciator for a focus adjusting device

Abstract

A focus adjusting device is a type of an autofocusing device having a servomechanism which drives the lens of a camera to bring it into focus. The focus adjusting device is provided with an annunciator for informing an operator of the state of focus of the camera lens. The annunciator is actuated after confirming the finish of the distance measuring operation of the device and the stop of the lens in the focused position.

What is claimed is: 
     
       1. An annunciator for a focus adjusting device for informing an operator of the in-focus state of lens means, said focus adjusting device comprising: focus detecting means for detecting the focusing condition of the lens means with respect to an object and for producing an output indicative of a focus condition;   a servomechanism for driving said lens means in response to the output of said focus detecting means to bring it into focus;   control means responsive to the output of said focus detecting means for actuating said annunciator when said lens means is in the in-focus state, said control means including filter means for eliminating a fluctuation of the output of said focus detecting means produced by the movement of said lens means relative to the object in the vicinity of the in-focus position, whereby a fluctuation of the annunciation of said annunciator is suppressed.   
     
     
       2. An annunciator for a focus adjusting device according to claim 1, wherein the focus adjusting operation finish annunciation is automatically stopped after the lapse of a certain predetermined time after the start of the annunciation. 
     
     
       3. An annunciator for a focus adjusting device according to claim 1, wherein a switch means for prohibiting the annunciation by the annunciator is provided. 
     
     
       4. An annunciator for a focus adjusting device according to claim 1, wherein lens driving means is provided at the side of the interchangeable lens of the camera.